001package org.cpsolver.ifs.constant; 002 003import org.cpsolver.ifs.model.Value; 004 005/** 006 * Extension of a variable with the possibility to have a constant value. 007 * 008 * Such variables are excluded from the solver process, however, they can be 009 * included in constraints. 010 * 011 * @version IFS 1.3 (Iterative Forward Search)<br> 012 * Copyright (C) 2006 - 2014 Tomáš Müller<br> 013 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br> 014 * <a href="http://muller.unitime.org">http://muller.unitime.org</a><br> 015 * <br> 016 * This library is free software; you can redistribute it and/or modify 017 * it under the terms of the GNU Lesser General Public License as 018 * published by the Free Software Foundation; either version 3 of the 019 * License, or (at your option) any later version. <br> 020 * <br> 021 * This library is distributed in the hope that it will be useful, but 022 * WITHOUT ANY WARRANTY; without even the implied warranty of 023 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 024 * Lesser General Public License for more details. <br> 025 * <br> 026 * You should have received a copy of the GNU Lesser General Public 027 * License along with this library; if not see <a href='http://www.gnu.org/licenses'>http://www.gnu.org/licenses</a>. 028 * 029 * @param <T> Value 030 */ 031public interface ConstantVariable<T extends Value<?, T>> { 032 /** True, if the variable is constant. 033 * @return true if constant 034 **/ 035 public boolean isConstant(); 036 037 /** Return assignment if constant 038 * @return constant value (if {@link ConstantVariable#isConstant()} is true) 039 **/ 040 public T getConstantValue(); 041}